I have a two computer both connected to the internet with Linksys router (ethernet). I want to be able to enable and disable the internet on the other computer from one of the computers. And the other user would need a password to enable it again. How would I do this, Im sure it would have to be a separate program.

I have access to both computers. They are both mine, both connected to the same router, but I want to control when the other computer can be connected to the internet, from this computer. And they don't use WiFi.

Well, it's rather hard...I never experienced something to turn internet on or off. The only reasonable way is to run Windows 2003 on the Terminal and disconnect it, but then, you;d need to get up and manually turn it on.